Optical disc recording method and apparatus

ABSTRACT

An optical disc recording method, comprises the steps of:a) forming a record signal in accordance with input information; b) generating a recording laser beam modulated with the record signal; c) controlling a laser radiation time at a record power for a 16x or higher write-speed to be (n+K)T for a pit length nT, where n=three to eleven, K is a constant (0≦K≦1.6), and T is a unit time corresponding to a pit length or a land length at a write-speed; and d) radiating the recording laser beam alternately at the recording power for the controlled radiating time to form pits and at a non-recording power to form lands toward a record surface of a recordable optical disc.

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application is based on Japanese Patent Application No.2001-141435, filed on May 11, 2001, the entire contents of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] A) Field of the Invention

[0003] The present invention relates to an optical disc recording methodand apparatus of a mark length recording type for recording informationin an optical disc by radiating a laser beam to the record surface ofthe disc and forming pits, and to technologies of improving the qualityof a signal recorded at a 16x write-speed or higher.

[0004] B) Description of the Related Art

[0005] The CD Write Once (CD-WO) standards (generally called the OrangeBook standards) are known as one recording method for recordable opticaldiscs. According to the CD-WO standards, information is recorded in anoptical disc as a combination of pit and land (between pits) having alength of 3T to 11T (at 1x, 1T={fraction (1/4.3218)} MHz=231 ns, at 2x,1T is ½ of the length at 1x, at 4x, 1T is ¼ of the length at 1x, at 6x,1T is ⅙ of the length at 1x, . . . ). As shown in FIG. 2, the power of arecording laser beam for a CD-WO disc (generally called a CD-R disc) isset to a recordable top power (record power) in a pit forming area andto a reproducible and unrecordable bottom power (reproduction power) ina land forming area. If a pit is formed by applying the top power duringthe period corresponding the pit length, the formed pit has a lengthlonger by about 1T because of remaining heat of the laser beam. To avoidthis, according to the conventional record strategy, the continuationperiod of the top power is controlled to be set to (n-K)T for each pitlength nT, where n=3, 4, . . . , 11 and K is a constant. The value ofthe constant K was given by the approximate equation (refer toJP-A-2000-11382):

K=−0.16x+1.2 for cyanine disc; and

K=−0.15x+1.15 for phthalocyanine disc

[0006] where x is a write-speed.

[0007] According to this approximate equation for the K value, the Kvalue decreases as the write-speed increases, and the sign of the Kvalue becomes negative at about the 8x write-speed. The K value at the16x write-speed is −1.36 for a cyanine disc and −1.25 for aphthalocyanine disc. Experiments made by the inventor have demonstrated,however, that 16x recording at this K value makes the continuationperiod of the top power still too long and the write signal quality islowered (large jitter and high error rate).

SUMMARY OF THE INVENTION

[0008] An object of this invention is to provide an optical discrecording method and apparatus capable of improving the quality of asignal recorded at a 16x write-speed or higher.

[0009] According to one aspect of the present invention, there isprovided an optical disc recording method, comprises the steps of: a)forming a record signal in accordance with input information; b)generating a recording laser beam modulated with the record signal; c)controlling a laser radiation time at a record power for a 16x or higherwrite-speed to be (n+K)T for a pit length nT, where n=three to eleven, Kis a constant (0≦K≦1.6), and T is a unit time corresponding to a pitlength or a land length at a write-speed; and d) radiating the recordinglaser beam alternately at the recording power for the controlledradiating time to form pits and at a non-recording power to form landstoward a record surface of a recordable optical disc.

[0010] More specifically, a laser radiation time of a record power for acyanine disc at a 16x write-speed is set to (n+K)T for a pit length nTwhere 0≦K≦0.5. A laser radiation time of a record power for aphthalocyanine disc at a 16x write-speed is set to (n+K)T for a pitlength nT where 0.5≦K≦1. A laser radiation time of a record power for asupercyanine disc at a 16x write-speed is set to (n+K)T for a pit lengthnT where 0.25≦K≦0.75. A laser radiation time of a record power for acyanine disc at a 20x write-speed is set to (n+K)T for a pit length nTwhere 0.25≦K≦0.75. A laser radiation time of a record power for aphthalocyanine disc at a 20x write-speed is set to (n+K)T for a pitlength nT where 0.75≦K≦1.25. A laser radiation time of a record powerfor a supercyanine disc at a 20x write-speed is set to (n+K)T for a pitlength nT where 0.5≦K≦1. A laser radiation time of a record power for acyanine disc at a 24x write-speed is set to (n+K)T for a pit length nTwhere 0.55≦K≦1.05. A laser radiation time of a record power for aphthalocyanine disc at a 24x write-speed is set to (n+K)T for a pitlength nT where 1.05≦K≦1.55. A laser radiation time of a record powerfor a supercyanine disc at a 24x write-speed is set to (n+K)T for a pitlength nT where 0.8≦K≦1.3.

[0011] In the optical disc recording method of recording information byradiating a recording laser beam modulated with a record signal toward arecord surface of a recordable optical disc and alternately forming pitsand lands by a mark length recording method, the laser radiation time ofa record power for a 16x write-speed or higher may be set to(n+K)T+α(nT) for a pit length nT where n=3, 4, . . . , 11, K is aconstant (0≦K≦1.6), T is a unit time corresponding to a pit length or aland length at a write-speed , and α(nT) is a correction amount for eachpit length [a correction amount added to the top power end timing (fordelaying the end of the top power) where α(3T)≧α(4T)≧α(5T)≧ . . .≧α(11T) and where α(3T)≧α(11T). In this case, for the 16x write-speed,α(3T) may be set to 0.05T≦α(3T)≦0.15T.

[0012] In the optical disc recording method of recording information byradiating a recording laser beam modulated with a record signal toward arecord surface of a recordable optical disc and alternately forming pitsand lands by a mark length recording method, the laser radiation time ofa record power for a 16x write-speed or higher may be set to(n+K)T+α(nT)−β(mT) for a pit length nT and a land length mT immediatelybefore the pit length where n, m=3, 4, . . . , 11, K is a constant(0≦K≦1.6), T is a unit time corresponding to a pit length or a landlength at a write-speed , α(nT) is a correction amount for each pitlength [a correction amount added to the top power end timing (fordelaying the end of the top power) where α(3T)≧α(4T)≧α(5T)≧ . . . ≧α(1T)and where α(3T)≧α(11T), and β(nt) is a correction amount for each landlength immediately before the pit length [a correction amount added tothe top power start timing (for delaying the start of the top power)where β(3T)≧β(4T)≧β(5T)≧ . . . ≧β(11T) and where β(3T) ≧β(11T). In thiscase, for the 16x write-speed, α(3T) may be set to 0.05T≦α(3T)≦0.15T andβ(3T) may be set to 0.05T≦β(3T)≦0.2T.

[0013] In the optical disc recording method of recording information byradiating a recording laser beam modulated with a record signal toward arecord surface of a recordable optical disc and alternately forming pitsand lands by a mark length recording method, the laser radiation time ofa record power for a 16x write-speed or higher may be set to(n+K)T+α(nT)−β(mT)−γ(m,n) for a pit length nT and a land length mTimmediately before the pit length where n, m=3, 4, . . . , 11, K is aconstant (0≦K≦1.6), T is a unit time corresponding to a pit length or aland length at a write-speed , α(nT) is a correction amount for each pitlength [a correction amount added to the top power end timing (fordelaying the end of the top power) where α(3T)≧α(4T)≧α(5T)≧ . . .≧α(11T) and where α(3T) ≧α(11T), β(nT) is a correction amount for eachland length immediately before the pit length [a correction amount addedto the top power start timing (for delaying the start of the top power)where β(3T)≧β(4T)≧β(5T)≧ . . . ≧β(11T) and where β(3T)≧β(11T), andγ(m,n) is a correction amount for each combination of a bit length and aland length immediately before the pit length [a correction amount addedto the top power start timing (for delaying the start of the top power)where γ(m,3)≦γ(m,4)≦γ(m,5)≦ . . . ≦γ(m,11) and whereγ(3,n)≦γ(4,n)≧γ(5,n)≧ . . . ≧γ(11,n). In this case, for the 16xwrite-speed, α(3T) may be set to 0.05T≦α(3T)≦0.15T, β(3T) may be set to0.05T≦β(3T)≦0.2T, γ(3,n) may be set to −0.1T≦γ(3,5)=γ(3,6)=γ(3,7)= . . .=γ(3,11)≦0T, and γ(4,n) may be set to −0.1T≦γ(4,5)=γ(4,6)=γ(4,7)= . . .=γ(4,11)≦0T.

[0014] In the optical disc recording method, a value of K recordedbeforehand in a guide groove of an optical disc during a discmanufacture process may be read and used for controlling the laserradiation time of the record power.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is a block diagram illustrating a record control to beexecuted by a system controller shown in FIG. 3.

[0016]FIG. 2 is a diagram showing the waveform of a recording laserbeam.

[0017]FIG. 3 is a block diagram showing the structure of an optical discrecording apparatus according to an embodiment of the invention.

[0018]FIG. 4 is a diagram illustrating an example of an operation ofcorrecting a record signal to be executed by a controller 38 shown inFIG. 1.

[0019]FIG. 5 is a graph showing the measurement results of the relationbetween an asymmetry value β and a pit jitter of a reproduced signalrecorded at a speed of 16x in a cyanine CD-R disc.

[0020]FIG. 6 is a graph showing the measurement results of the relationbetween an asymmetry value β and a pit jitter of a reproduced signalrecorded at a speed of 16x in a phthalocyanine CD-R disc.

[0021]FIG. 7 is a graph showing the measurement results of the relationbetween an asymmetry value β and a pit jitter of a reproduced signalrecorded at a speed of 16x in a supercyanine CD-R disc.

[0022]FIG. 8 is a graph showing the measurement results of the relationbetween an asymmetry value β and a land jitter of a reproduced signalrecorded at a speed of 16x in a cyanine CD-R disc.

[0023]FIG. 9 is a graph showing the measurement results of the relationbetween an asymmetry value β and a land jitter of a reproduced signalrecorded at a speed of 16x in a phthalocyanine CD-R disc.

[0024]FIG. 10 is a graph showing the measurement results of the relationbetween an asymmetry value β and a land jitter of a reproduced signalrecorded at a speed of 16x in a supercyanine CD-R disc.

[0025]FIG. 11 is a graph showing the measurement results of the relationbetween an asymmetry value β and a pit jitter of a reproduced signalrecorded at a speed of 16x in a cyanine CD-R disc with a corrected Kvalue and with and without a correction by +α(nT)−β(mT)−γ(m,n).

[0026]FIG. 12 is a graph showing the measurement results of the relationbetween an asymmetry value β and a pit jitter of a reproduced signalrecorded at a speed of 16x in a phthalocyanine CD-R disc with acorrected K value and with and without a correction by+α(nT)−β(mT)−γ(m,n).

[0027]FIG. 13 is a graph showing the measurement results of the relationbetween an asymmetry value β and a pit jitter of a reproduced signalrecorded at a speed of 16x in a supercyanine CD-R disc with a correctedK value and with and without a correction by +α(nT)−β(mT)−γ(m,n).

[0028]FIG. 14 is a graph showing the measurement results of the relationbetween an asymmetry value β and a land jitter of a reproduced signalrecorded at a speed of 16x in a cyanine CD-R disc with a corrected Kvalue and with and without a correction by +α(nT)−β(mT)−γ(m,n).

[0029]FIG. 15 is a graph showing the measurement results of the relationbetween an asymmetry value β and a land jitter of a reproduced signalrecorded at a speed of 16x in a phthalocyanine CD-R disc with acorrected K value and with and without a correction by+α(nT)−β(mT)−γ(m,n).

[0030]FIG. 16 is a graph showing the measurement results of the relationbetween an asymmetry value β and a land jitter of a reproduced signalrecorded at a speed of 16x in a supercyanine CD-R disc with a correctedK value and with and without a correction by +α(nT)−β(mt)−γ(m,n).

[0031]FIG. 17 is a graph showing the measurement results of the relationbetween an asymmetry value β and a pit jitter of a reproduced signalrecorded at a speed of 20x in a cyanine CD-R disc.

[0032]FIG. 18 is a graph showing the measurement results of the relationbetween an asymmetry value β and a pit jitter of a reproduced signalrecorded at a speed of 20x in a phthalocyanine CD-R disc.

[0033]FIG. 19 is a graph showing the measurement results of the relationbetween an asymmetry value β and a pit jitter of a reproduced signalrecorded at a speed of 20x in a supercyanine CD-R disc.

[0034]FIG. 20 is a graph showing the measurement results of the relationbetween an asymmetry value β and a land jitter of a reproduced signalrecorded at a speed of 20x in a cyanine CD-R disc.

[0035]FIG. 21 is a graph showing the measurement results of the relationbetween an asymmetry value β and a land jitter of a reproduced signalrecorded at a speed of 20x in a phthalocyanine CD-R disc.

[0036]FIG. 22 is a graph showing the measurement results of the relationbetween an asymmetry value β and a land jitter of a reproduced signalrecorded at a speed of 20x in a supercyanine CD-R disc.

[0037]FIG. 23 is a graph obtained by experiments and showing the properrange of the K value at each write-speed for a cyanine CD-R disc.

[0038]FIG. 24 is a graph obtained by experiments and showing the properrange of the K value at each write-speed for a phthalocyanine CD-R disc.

[0039]FIG. 25 is a graph obtained by experiments and showing the properrange of the K value at each write-speed for a supercyanine CD-R disc.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0040] Description will be made on the preferred embodiments of theinvention, referring to the drawings. FIG. 3 is a block diagram showingthe system structure of an optical disc writing/reading apparatusaccording to an embodiment of the invention.

[0041] An operator sets a write-speed from an input unit 28. In responseto a command from a system controller 19, a disc servo circuit 16rotates a spindle motor 12 at the set write-speed and at a constantlinear speed (at 1x, 1.2 m/s to 1.4 m/s, at 2x, two times the speed of1x, at 4x, four times the speed of 1x, . . . ). This constant linearspeed control can be realized through phase locked loop (PLL) control ofthe spindle motor 12 in such a manner that a signal detected from awobble in the pregroove set to 22.05 kHz in the case of the CD-WOstandards signal can be detected at a predetermined frequency (at 1x,22.05 kHz, at 2x, 44.1 kHz, at 4x, 88.2 kHz, . . . ).

[0042] In accordance with a command from the system controller 19, afocus/tracking serve circuit 18 controls the focus and tracking of alaser beam 11 to be radiated from a semiconductor laser in an opticalhead 13. The tracking control is performed by detecting the pregrooveformed on the optical disc 10. In accordance with a command from thesystem controller 19, a feed serve circuit 17 drives a feed motor 20 tomove the optical head 13 along the radial direction of an optical disc10.

[0043] If a signal to be recorded in the optical disc (CD-R disc) 10 isa digital signal, it is directly input to a record signal formingcircuit 22 at a speed corresponding the write-speed, whereas if thesignal is an analog signal, it is input via an A/D converter 24 to therecord signal forming circuit 22. The record signal forming circuit 22interleaves the input data, adds an error check code, and adds TOCinformation and sub-code information generated by a sub-code generatorcircuit 23. This data is then EFM modulated to generate a series ofserial data having the format of the CD standard at a transfer ratecorresponding to the write-speed and output this serial data as recordsignals. The record signals are supplied via a drive interface 15 to arecord signal correcting circuit 26 whereat the record signals arecorrected based upon record strategy selected in accordance with a disctype (dye type), linear speed, write-speed and the like, and input to alaser generating circuit 25. In accordance with the record signal, helaser generating circuit 25 drives the semiconductor laser in theoptical head 13 and radiates a laser beam 11 to the record surface ofthe optical disc 10 to form pits in the disc. The power of a laser beamis designated by the write-speed and, if necessary, the linear speed,and an automatic laser power control (ALPC) circuit controls the laserpower to have the designated power at a high precision. In this manner,data having the format, transfer speed and linear speed (1.2 to 1.4 m/s)of the CD-WO standards is recorded in the optical disc 10. Areproduction laser beam (having a power smaller than the record power)is applied to the optical disc 10 to reproduce the recorded data. Theread data is then demodulated by a signal reproduction circuit 30 andoutput directly as digital signals or via a D/A converter 31 as analogsignals.

[0044]FIG. 1 is a block diagram illustrating a record control to beexecuted by the system controller 19 shown in FIG. 3. Awrite-speed-setting unit 28 corresponds to the input unit 28 shown inFIG. 3. An operator sets a write-speed (1x, 2x, 4x . . . ). A disctype—linear speed judging unit 32 judges the linear speed and the disctype of the optical disc 10 set to the apparatus. For example, the disctype can be judged from the disc type information in a disc IDprerecorded in the optical disc 10 during a disc manufacture process.The linear speed can be judged by reading a record time (63 minutestype, 74 minutes type, and intermediate type) recorded in an ATIP signalin the disc lead-in part and corresponding to the linear speed (1.4 m/sfor 63 minutes type and 1.2 m/s for 74 minutes type), or calculated froman encoder output of the spindle motor. A record strategy memory unit 34stores optimum record strategies (time axis correction amount, recordpower and the like) for each combination of disc type, linear speed andwrite-speed). A record strategy selection unit 36 reads thecorresponding record strategy from the record strategy memory unit 34 byusing as search keys an input disc type, linear speed and write-speed.In accordance with the read record strategy, a controller 38 controls arecord signal correction circuit 26 to correct the lengths of bits andlands of record signals. The controller 38 also controls the lasergenerator circuit 25 to control the laser power. The controller 38controls a disc servo circuit 16 to rotate the spindle motor 12 at thespeed corresponding to the designated write-speed.

[0045]FIG. 4 is a diagram illustrating an example of an operation ofcorrecting a record signal to be executed by the controller 38. In FIG.4, the waveform of a record signal before correction is indicated at(a), the waveform of the record signal corrected with +KT is indicatedat (b), and the waveform of a laser drive signal further corrected with+α(nT), −β(mT), and −γ(m, n) is indicated at (c). With the correction by+KT at (b), the end time of the record power of the record signal beforecorrection at (a) is corrected in accordance with the disc type (dyetype) and write-speed. If the K value is positive, the end time isdelayed (the continuation period of the record power is prolonged),whereas if the K value is negative, the end time is advanced (thecontinuation period of the record power is shortened). The K value isgenerally positive at the 16x write-speed or higher, and the end time isdelayed. With the correction by +α(nT) at (c), the end time of therecord power corrected by KT is further minutely adjusted in accordancewith the bit length nT. If the value α(nT) is positive, the end time isdelayed, whereas if it is negative, the end time is advanced. The valueα(nT) is set as α(3T)≧α(4T)≧α(5T)≧ . . . ≧α(11T) where α(3T)>α(11T).With the correction by −β(mT) at (c), the start time of the record powerof the record signal is finely adjusted in accordance with the blanklength mT immediately before the pit. If the value β(mT) is positive,the start time is delayed (the continuation period of the record poweris shortened), whereas if it is negative, the start time is advanced(the continuation period of the record power is prolonged). The valueβ(mT) is set as β(3T)≧β(4T)≧β(5T)≧ . . . ≧β(11T) where β(3T)>β(11T).With the correction by −γ(m,n) at (c), the start time of the recordpower of the record signal is further minutely adjusted in accordancewith a combination of the blank length mT immediately before the pit andthe pit length nT. If the value γ(m,n) is positive, the start time isdelayed, whereas if it is negative, the start time is advanced. Thevalue γ(m,n) is set as γ(m,3)≦γ(m,4)≦γ(m,5)≦ . . . ≦γ(m,11) andγ(3,n)≧γ(4,n)≧γ(5,n)≧ . . . ≧γ(11, n).

[0046] The radiation time control of a recording laser beam to beexecuted by the controller 38 will be described. FIGS. 5 to 22 aregraphs showing the measurement results of the relation between anasymmetry value β and a pit jitter of a reproduced signal recorded atvarious record powers in CD-R discs of various dye types. The asymmetryvalue β is a parameter related to a record depth and changes with arecord power. The asymmetry value β is a parameter different from thecorrection amount β(mT) of the record strategy. The asymmetry valueβ(mt) is calculated from (a+b)/(a−b) where a is a peak level (positivesign) of a reproduced EFM signal waveform and b is a bottom level(negative sign). The record strategy ensuring a high record signalquality is the strategy which allows a low jitter (i.e., a wide jittermargin) in a wider range of the asymmetry value β on the high asymmetryvalue β side.

[0047] FIGS. 5 to 7 are graphs showing the measurement results of bitjitters of reproduced signals recorded at the speed of 16x in discs ofvarious dye types and at various K values of the record strategy (n+K)T,and FIGS. 8 to 10 are graphs showing the measurement results of landjitters. From these graphs, the optimum values of K which allow a widerjitter margin on the high asymmetry value β side are given as:

[0048] Cyanine: K=0

[0049] Phthalocyanine: K=0.75

[0050] Supercyanine: K=0.5

[0051] If the correction of +α(nT)−β(mT)−γ(m,n) is to be added, forexample, the following values are set:

[0052] 0.05T≦α(3T)≦0.15T

[0053] 0.05T≦β(3T)≦0.2T

[0054] −0.1T≦γ(3,5)=γ(3,6)=γ(3,7)= . . . =γ(3,11)≦0T

[0055] −0.1T≦γ(4,5)=γ(4,6)=γ(4,7)= . . . =γ(4,11)≦0T

[0056] The measurement results of pit jitters are shown in FIGS. 11 to13 and the measurement results of land jitters are shown in FIGS. 14 to16, respectively when the correction of +α(nT)−β(mT)−γ(m,n) is added andnot added, with the above-described optimum values for the dye typebeing set as the K values. It can be understood from these graphs that awider jitter margin can be obtained by adding the correction of+α(nT)−β(mT)−γ(m,n).

[0057] FIGS. 17 to 19 are graphs showing the measurement results of bitjitters of reproduced signals recorded at the speed of 20x in discs ofvarious dye types and at various K values of the record strategy (n+K)T,and FIGS. 20 to 22 are graphs showing the measurement results of landjitters. From these graphs, the optimum values of K which allow a widerjitter margin on the high asymmetry value β side are given as:

[0058] Cyanine: K=0.5

[0059] Phthalocyanine: K=1

[0060] Supercyanine: K=0.75

[0061] Also in the 20x record, a wider jitter margin can be obtained byadding the correction of+α(nT)−β(mT)−γ(m,n).

[0062] FIGS. 23 to 25 are graphs obtained by experiments and showing theproper ranges of the K value at each write-speed for each dye type. Fromthese graphs, the proper ranges of the K value for each write-speed andeach dye type are given by:

[0063] (16x record)

[0064] Cyanine: 0≦K≦0.5

[0065] Phthalocyanine: 0.5≦K≦1

[0066] Supercyanine: 0.25≦K≦0.75

[0067] (20x record)

[0068] Cyanine: 0.25≦K≦0.75

[0069] Phthalocyanine: 0.75≦K≦1.25

[0070] Supercyanine: 0.5≦K≦1

[0071] (22x record)

[0072] Cyanine: 0.55≦K≦1.05

[0073] Phthalocyanine: 1.05≦K≦1.55

[0074] Supercyanine: 0.8≦K≦1.3

[0075] It can be understood from these values that the K value isincreased as the write-speed becomes larger and that the K value is maderelatively small for cyanine, relatively large for phthalocyanine, andintermediate for supercyanine. At each write-speed, the correction of+α(nT)−β(mT)−γ(m,n) can be added.

[0076] The K value to be used for each disc type and each write-speedmay be stored beforehand in the record strategy memory unit 34. When anoptical disc 10 is set, the disc ID is read and the K value is read fromthe record strategy memory unit 34 in accordance with a combination ofthe disc ID and a designated write-speed. Alternatively, the K value maybe recorded beforehand in the pregroove (guide groove) of an opticaldisc 10 as ATIP special information during a disc manufacture process.When the optical disc 10 is set to an optical disc recording apparatus,the K value is read from the optical disc 10. In this case, the useamount of the memory (record strategy memory unit 34) can be reduced.

[0077] The present invention has been described in connection with thepreferred embodiments. The invention is not limited only to the aboveembodiments. It is apparent that various modifications, improvements,combinations, and the like can be made by those skilled in the art.

What are claimed are:
 1. An optical disc recording method, comprisingthe steps of: a) forming a record signal in accordance with inputinformation; b) generating a recording laser beam modulated with therecord signal; c) controlling a laser radiation time at a record powerfor a 16x or higher write-speed to be (n+K)T for a pit length nT, wheren=three to eleven, K is a constant (0≦K≦1.6), and T is a unit timecorresponding to a pit length or a land length at a write-speed; and d)radiating the recording laser beam alternately at the recording powerfor the controlled radiating time to form pits and at a non-recordingpower to form lands toward a record surface of a recordable opticaldisc.
 2. An optical disc recording method according to claim 1, furthercomprising the steps of reading a K value, from a guide groove of therecordable optical disc, recorded beforehand in a manufacturing processof the recordable optical disc, and wherein the controlling step (c)uses the K value read from the guided groove.
 3. An optical discrecording method, comprising the steps of: a) forming a record signal inaccordance with input information; b) generating a recording laser beammodulated with the record signal; c) controlling a laser radiation timeat a record power for a cyanine disc at a 16x write-speed to be (n+K)Tfor a pit length nT, where n=three to eleven, K is a constant (0≦K≦0.5),and T is a unit time corresponding to a pit length or a land length at a16x write-speed; and d) radiating the recording laser beam alternatelyat the recording power for the controlled radiating time to form pitsand at a non-recording power to form lands toward a record surface of arecordable optical disc.
 4. An optical disc recording method, comprisingthe steps of: a) forming a record signal in accordance with inputinformation; b) generating a recording laser beam modulated with therecord signal; c) controlling a laser radiation time at a record powerfor a phthalocyanine disc at a 16x write-speed to be (n+K)T for a pitlength nT, where n=three to eleven, K is a constant (0.5≦K≦1), and T isa unit time corresponding to a pit length or a land length at a 16xwrite-speed; and d) radiating the recording laser beam alternately atthe recording power for the controlled radiating time to form pits andat a non-recording power to form lands toward a record surface of arecordable optical disc.
 5. An optical disc recording method, comprisingthe steps of: a) forming a record signal in accordance with inputinformation; b) generating a recording laser beam modulated with therecord signal; c) controlling a laser radiation time at a record powerfor a supercyanine disc at a 16x write-speed to be (n+K)T for a pitlength nT, where n=three to eleven, K is a constant (0.25≦K≦0.75), and Tis a unit time corresponding to a pit length or a land length at a 16xwrite-speed; and d) radiating the recording laser beam alternately atthe recording power for the controlled radiating time to form pits andat a non-recording power to form lands toward a record surface of arecordable optical disc.
 6. An optical disc recording method, comprisingthe steps of: a) forming a record signal in accordance with inputinformation; b) generating a recording laser beam modulated with therecord signal; c) controlling a laser radiation time at a record powerfor a cyanine disc at a 20x write-speed to be (n+K)T for a pit lengthnT, where n=three to eleven, K is a constant (0.25≦K≦0.75), and T is aunit time corresponding to a pit length or a land length at a 20xwrite-speed; and d) radiating the recording laser beam alternately atthe recording power for the controlled radiating time to form pits andat a non-recording power to form lands toward a record surface of arecordable optical disc.
 7. An optical disc recording method, comprisingthe steps of: a) forming a record signal in accordance with inputinformation; b) generating a recording laser beam modulated with therecord signal; c) controlling a laser radiation time at a record powerfor a phthalocyanine disc at a 20x write-speed to be (n+K)T for a pitlength nT, where n=three to eleven, K is a constant (0.75≦K≦1.25), and Tis a unit time corresponding to a pit length or a land length at a 20xwrite-speed; and d) radiating the recording laser beam alternately atthe recording power for the controlled radiating time to form pits andat a non-recording power to form lands toward a record surface of arecordable optical disc.
 8. An optical disc recording method, comprisingthe steps of: a) forming a record signal in accordance with inputinformation; b) generating a recording laser beam modulated with therecord signal; c) controlling a laser radiation time at a record powerfor a supercyanine disc at a 20x write-speed to be (n+K)T for a pitlength nT, where n=three to eleven, K is a constant (0.5≦K≦1), and T isa unit time corresponding to a pit length or a land length at a 20xwrite-speed; and d) radiating the recording laser beam alternately atthe recording power for the controlled radiating time to form pits andat a non-recording power to form lands toward a record surface of arecordable optical disc.
 9. An optical disc recording method, comprisingthe steps of: a) forming a record signal in accordance with inputinformation; b) generating a recording laser beam modulated with therecord signal; c) controlling a laser radiation time at a record powerfor a cyanine disc at a 24x write-speed to be (n+K)T for a pit lengthnT, where n=three to eleven, K is a constant (0.55≦K≦1.05), and T is aunit time corresponding to a pit length or a land length at a 24xwrite-speed; and d) radiating the recording laser beam alternately atthe recording power for the controlled radiating time to form pits andat a non-recording power to form lands toward a record surface of arecordable optical disc.
 10. An optical disc recording method,comprising the steps of: a) forming a record signal in accordance withinput information; b) generating a recording laser beam modulated withthe record signal; c) controlling a laser radiation time at a recordpower for a phthalocyanine disc at a 24x write-speed to be (n+K)T for apit length nT, where n=three to eleven, K is a constant (1.05≦K≦1.55),and T is a unit time corresponding to a pit length or a land length at a24x write-speed; and d) radiating the recording laser beam alternatelyat the recording power for the controlled radiating time to form pitsand at a non-recording power to form lands toward a record surface of arecordable optical disc.
 11. An optical disc recording method,comprising the steps of: a) forming a record signal in accordance withinput information; b) generating a recording laser beam modulated withthe record signal; c) controlling a laser radiation time at a recordpower for a supercyanine disc at a 24x write-speed to be (n+K)T for apit length nT, where n=three to eleven, K is a constant (0.8≦K≦1.3), andT is a unit time corresponding to a pit length or a land length at a 24xwrite-speed; and d) radiating the recording laser beam alternately atthe recording power for the controlled radiating time to form pits andat a non-recording power to form lands toward a record surface of arecordable optical disc.
 12. An optical disc recording apparatus,comprising: a record signal forming device that forms a record signal inaccordance with input information; a generator that generates arecording laser beam modulated with the record signal; a controller thatcontrols a laser radiation time at a record power for a 16x or higherwrite-speed to be (n+K)T for a pit length nT, where n=three to eleven, Kis a constant (0≦K≦1.6), and T is a unit time corresponding to a pitlength or a land length at a write-speed; and a radiator that radiatesthe recording laser beam alternately at the recording power for thecontrolled radiating time to form pits and at a non-recording power toform lands toward a record surface of a recordable optical disc.